As is known, climbing shoes normally comprise an appropriately shaped leather vamp; a flexible, cured rubber sole glued to the bottom of the vamp; and a number of highly elastic rubber bindings glued to the vamp to surround and grip the foot as tightly as the user can physically withstand, while at the same time enabling the shoe to effectively enclose the foot so the user's weight can be placed safely on the tip of the foot.
More specifically, climbing shoes normally comprise a first substantially horseshoe-shaped binding, traditionally called “tip binding”, that covers the portion of the vamp surrounding the metatarsus-phalanx area of the sole of the foot; and a second binding, traditionally called “heel binding”, which covers the area of the vamp directly over the heel of the foot (i.e. the part of the foot where the Achilles' tendon joins the calcaneus) and extends along the sides of the vamp up to the sides of the metatarsus-phalanx area of the sole of the foot, where it is connected to the first binding to form a sort of annular elastic tie tightly surrounding and enclosing the foot.
Obviously, the first binding partly covers the bottom of the vamp corresponding to the metatarsus-phalanx area of the sole of the foot; and the flexible, cured rubber sole is glued to the bottom of the vamp, partly over the first and second binding, to form, with the first and second binding, a sort of elastic sheath or cap enclosing and protecting the tip of the foot, and which is connected elastically to the heel of the foot by the second binding.
More recently, climbing shoes have been marketed, in which the cured rubber sole only covers the bottom of the vamp at the metatarsus-phalanx area of the sole of the foot; and the second or “heel” binding only extends along one side of the vamp to cover the bottom of the vamp in the arch and metatarsus-phalanx areas of the sole of the foot, obviously beneath the cured rubber sole. In this case, the shoe also comprises a third binding glued to the bottom of the vamp in the tarsus-calcaneus area, and which extends on the rear of the vamp to also cover the heel area, and is connected to the second or “heel” binding.